1. Field of the Invention
This invention relates to foodstuffs in general, and, in particular, to a process cheese analog resembling natural process cheese in body, texture, and flavor and to the method of manufacturing such a process cheese analog.
2. Description of the Prior Art
Process cheese is conventionally manufactured from natural cheese through a cooking of the natural cheese together with the addition thereto of various spices, flavorings, and emulsifiers. Since the main ingredient in this processing is mostly natural cheese, the resultant process cheese conventionally contains all the fat component of natural cheese itself, together with the other ingredients as they are added, and the cost of the process cheese is usually determined by the relatively high cost of natural cheese.
Process cheese-like products are conventionally negregated into three categories depending on their fat and moisture contents, process cheese, process cheese food, and process cheese spread. Process cheese is defined to have the highest fat content and the lowest moisture content, process cheese spread is defined to have the lowest fat content and the highest moisture content, and process cheese food is defined to be intermediate in both fat and moisture content.
Natural cheese itself is conventionally manufactured from whole milk, skim milk, nonfat dry milk, cream or combinations thereof. The milk product is first acidified, usually using a lactic acid producing bacterial culture, after which a coagulum is then formed in the acidified milk by adding thereto a milk coagulating enzyme. The resultant custard-like coagulum or curd is then cut into numerous particles and heated to facilitate the separation of whey from the curd. The whey is then removed from the curd, usually by simple drainage, and the curd is salted and pressed into forms to produce solid blocks of cheese. The cheese is then cured in temperature controlled conditions until the desired texture and flavor is achieved. The whey by-product of the cheese making process is often considered a waste product and is available in excess in all cheese making regions. Disposal of the whey is often a pollution problem and many efforts have been undertaken to recover the nutrients contained in this whey. The whey usually also contains a significant amount, in the range of 7 to 10 percent, of the fat component contained in the original milk product. This fat is primarily removed from the milk during the curd cutting process. The fat is trapped in curd in small particles which are wholly contained within the curd particles. Cutting the curd exposes many of the fat particles which are then leached out with the whey. The loss of this fat is a significant monetary factor and represents the loss of a considerable portion of the recoverable material from the milk and yet is completely unavoidable during conventional cheese manufacture.
The prior art contains many examples of foodstuffs utilizing therein materials derived from waste cheese whey. Some of these processes involve precipitation of remaining solids from the whey while others use the liquid whey combined with other nutritive ingredients to make diverse products. Examples of such foodstuffs and the methods for their manufacture are shown in U.S. Pat. Nos. 3,421,897; 3,466,176; 3,704,136; 3,780,182; 3,618,109; 3,922,375; 3,943,264; 3,956,520; and 4,036,999.
Another product of commerce often produced from whole milk is dry casein material. The casein is produced from milk through the direct acidification of the fat-free portion of a milk product until a curd forms. The casein is normally formed into this curd through the use of mineral, i.e., hydrochloric or sulphuric acids, but may also be created through the use of lactic acid generated in a milk culture by microorganisms. The casein curd is repeatedly washed to remove the remaining lactose and salt therefrom after which the washed curd is passed through a press to remove water therefrom and is then passed through hot driers which reduce the water content of the curd to approximately 10 percent. The dried curd is then reduced to the desired size by grinding to produce a dry powder or granular product. This product consists either of dry casein alone or as casein combined with an alkaline earth, such as calcium, to produce a caseinate compound, such as calcium caseinate. These dry casein materials, containing most of the protein constituents of whole milk, can be easily and economically stored and shipped and are normally commercially available throughout the world at a lower price per-pound-protein than whole milk. Because of its cost advantage numerous processes have been developed to fabricate cheese-like products or cheese extenders from casein materials. However, these cheese-like products or extenders do not satisfactorily resemble either natural cheese or processed cheese and are readily distinguishable therefrom by taste and texture. Examples of such products and the methods for their manufacture are shown in U.S. Pat. Nos. 3,397,994; 3,397,995; 3,720,520; 3,886,300; 3,917,854; 3,922,374; 3,941,891; and 4,016,298.
It has also been proposed in at least one instance to use whey as a carrier for a selected fat, with the whey then being combined with a non-fat portion of milk and the resultant combination being used as a feed substance in a cheese making procedure. Such a procedure, which substitutes for the fat normally found in milk, is described in U.S. Pat. No. 3,899,605. The problem with this procedure is that liquid skim milk or other liquid milk fraction must still be used in the manufacture thereby losing the cost advantage possible by using a dry powered casein material. This procedure also introduces the fat into the cheese at the very start of the procedure. Other methods for substituting emulsified fats in milk solutions for use in making cheese are disclosed in U.S. Pat. Nos. 3,716,377 and 3,889,004.
There have been at least some attempts to introduce oils into cheese-like products during some sort of processing operation, as exemplified by U.S. Pat. Nos. 3,814,825 and 3,929,892. Neither of these processes involves the production of a fat-free cheese analog to which fats may be added during processing, however.